In this paper we present the fusion of generalized LR parsing and
scannerless parsing. This combination supports syntax definitions in
which all aspects (lexical and context-free) of the syntax of a
language are defined explicitly in one formalism. Furthermore, there
are no restrictions on the class of grammars, thus allowing a natural
syntax tree structure.
Ambiguities that arise through the use of unrestricted grammars are
handled by explicit disambiguation constructs, instead of implicit
defaults that are taken by traditional scanner and parser generators.
Hence, a syntax definition becomes a full declarative description of a
language. Disambiguation constructs can be interpreted as filters on
parse forests. Scannerless generalized LR parsing is a viable technique that has been
applied in various industrial and academic projects.

This paper, "Disambiguation Filters for Scannerless Generalized LR Parsers," is
about a systematic way of dealing with the problem of parsing with ambiguous
grammars.

I thought this paper was wonderful. Sure it has some flaws, but I think it and
all the SGLR papers should be required reading by all faculty who teach
compilers and all graduate students who will someday teach compilers. Why?
Because SGLR represents so many advantages over the lex+yacc or hand-coded
lexer+parser models that the only compelling reason that I can think of to not
teach SGLR is, as Homer Simpson would say, "It's a good idea, but it's a new
idea, and, therefore, I fear it and must reject it."
(OK, it does have one disadvantage that is serious, speed, but that's not
enough of a concern to eliminate it from all compiler jobs.)

So, what's SGLR? It's a system of handling all lexical and parsing concerns
within a unified Generalized LR parser. This unified system has advantages
galore, which are well-described in the paper. Because it uses GLR parsing
technology it allows ambiguous grammars. This paper describes 4 mechanisms
that allow for declarative disambiguation of the resulting parses. All four
are well described and carefully analyzed.